Graceful termination of a web enabled client

Abstract

In an embodiment, a client-server based project schedule management system comprises a task editor accessible through a web browser to perform various scheduling tasks by members of a project. A web enabled client receives browser executable code from a web server. The executable code includes an exception handler coded in JavaScript. A portion of the received code is executed within the exception handler to determine whether an abnormal condition has been encountered. If an abnormal condition has been encountered, the exception handler calls one or more global functions to gracefully terminate execution of the client-side browser executable code, clears the currently displayed browser window and displays an error message in the browser window. The exception handler includes one or more JavaScript try and catch block statements. The displayed error message may be used to provide notice to a user of the client that the task editor session has failed and/or output diagnostic information associated with the abnormal condition.

1 . A computer implemented method comprising:
 receiving browser executable code from a web server for at least displaying a user input form associated with the task editor in a browser window;   executing at least a portion of the received code within an exception handler;   determining whether an abnormal condition is encountered within the exception handler; and,   when an abnormal condition is encountered, calling one or more global functions which when executed cause terminating execution of the browser executable code, clearing the displayed browser window and displaying an error message in the browser window of the client.   
   
   
       2 . The method according to  claim 1  wherein the received browser executable code is programmed in JavaScript. 
   
   
       3 . The method according to  claim 1  wherein the exception handler includes one or more Try and Catch Block statements. 
   
   
       4 . The method according to  claim 1  wherein the displayed error message provides diagnostic information associated with the abnormal condition. 
   
   
       5 . The method according to  claim 1  wherein the displayed error message provides notice to a user of the client that the task editor has failed. 
   
   
       6 . The method of  claim 1  wherein the browser executable code is programmed in a programming language that has no inherent language construct that can be used to cause termination of a program written in that language. 
   
   
       7 . A data processing system comprising:
 a web server in networking communications with a web browser enabled client, the web enabled client including;   a processor;   a memory coupled to the processor having instructions which when executed by the processor causes the processor to:   receive browser executable code from the web server to at least display a web page associated with the task editor in a browser window;   execute at least a portion of the received executable code within an exception handler;   determine whether an abnormal condition is encountered within the exception handler; and,   if an abnormal condition is encountered, call one or more global functions to terminate execution of the browser executable code on the client, clear the displayed browser window and display an error message in the browser window.   
   
   
       8 . The system according to  claim 7  wherein the received browser executable code is programmed in JavaScript. 
   
   
       9 . The system according to  claim 7  wherein the exception handler includes one or more Try and Catch Block statements. 
   
   
       10 . The system according to  claim 7  wherein the displayed error message provides diagnostic information associated with the abnormal condition. 
   
   
       11 . The system according to  claim 7  wherein the displayed error message provides notice to a user of the client that the task editor has failed. 
   
   
       12 . The system of  claim 1  wherein the browser executable code is programmed in a programming language that has no inherent language construct that can be used to cause termination of a program written in that language. 
   
   
       13 . A computer program product embodied in a tangible form on a computer readable storage medium comprising instructions which when executed by a processor associated with a web enabled client, causes the processor to:
 receive browser executable code from a web server for display of a web page associated with a task editor;   execute at least a portion of the received code within an exception handler;   determine whether an abnormal condition is encountered within the exception handler; and,   when an abnormal condition is encountered, call one or more global functions to terminate execution of the browser executable code on the client, clear the displayed browser window and display an error message in the browser window.   
   
   
       14 . The computer program product according to  claim 13  wherein the received browser executable code is programmed in JavaScript. 
   
   
       15 . The computer program product according to  claim 13  wherein the exception handler includes one or more Try and Catch Block statements. 
   
   
       16 . The computer program product according to  claim 13  wherein the displayed error message provides diagnostic information associated with the abnormal condition. 
   
   
       17 . The computer program product according to  claim 13  wherein the displayed error message provides notice to a user of the client that the task editor has failed. 
   
   
       18 . The computer program product of  claim 13  wherein the browser executable code is programmed in a programming language that has no inherent language construct that can be used to cause termination of a program written in that language. 
   
   
       19 . A computer-readable medium comprising one or more sequences of instructions which when executed by one more processors cause the one or more processors to:
 receive JavaScript code from a web server for display of a web page associated with a task editor;   execute at least a portion of the received code within an exception handler that comprises one or more Try and Catch Block statements;   determine whether an abnormal condition is encountered within the exception handler; and,   when an abnormal condition is encountered, call one or more global functions to terminate execution of the browser executable code on the client, clear the displayed browser window and display an error message in the browser window; wherein the displayed error message provides diagnostic information associated with the abnormal condition or provides notice to a user of the client that the task editor has failed.   
   
   
       20 . A data processing apparatus comprising:
 means for receiving browser executable code from a web server for at least displaying a user input form associated with the task editor in a browser window;   means for executing at least a portion of the received code within an exception handler;   means for determining whether an abnormal condition is encountered within the exception handler; and,   means for calling, when an abnormal condition is encountered, one or more global functions which when executed cause terminating execution of the browser executable code, clearing the displayed browser window and displaying an error message in the browser window of the client.   
   
   
       21 . The apparatus of  claim 20  wherein the received browser executable code is programmed in JavaScript. 
   
   
       21 . The apparatus of  claim 20  wherein the exception handler includes one or more Try and Catch Block statements. 
   
   
       22 . The apparatus of  claim 20  wherein the displayed error message provides diagnostic information associated with the abnormal condition or provides notice to a user of the client that the task editor has failed. 
   
   
       23 . The apparatus of  claim 20  wherein the browser executable code is programmed in a programming language that has no inherent language construct that can be used to cause termination of a program written in that language.